on here and on the playgroup (whenever you need to know) where their kids are developmentally and you will see a wide healthy range. The internet is just as bad a source for this type of info because again, it is written by so called experts.
My dk's were never where the recommendations said they should be. Given that they were way ahead, still, for a parent whose child is perfectly normal and developing healthy, it can be discouraging to read that your child is not where the "Recommendation" is that they should be. Also children go through growth spurts at different speeds.
I would just ditch it all and if you have questions, get answers from real time moms, with real life experiences who you have formed a bond with and who aren't trying to out-do you or your child, kwim? Most of these text book situations/advice that one can read has caused more worry then they are worth.
Just my 10 pence.